In the highly sophisticated art of modern key-lock systems multiple independent locks can be operated by one or more independent keys and multiple independent keys can operate the same lock. These systems are based on two way communication between keys and locks. The release operation of the lock depends on the coincidence between the key-code transmitted by the key and the release-code stored in the lock.
For security reasons the key-code gets transmitted only upon receiving a trigger-code from the lock. In order to further enhance security these transmitted codes get scrambled or changed after each use.
The problem of establishing and reorganizing key-lock assignments in an easy and flexible way, without restricting the security of systems, is not satisfactorily solved yet.